A new survey of variation and change in Canadian English, called Dialect Topography, has been extended from Southern Ontario, where it was conceived and originally implemented, to Montreal. In the tradition of earlier questionnaires investigating Canadian English, the new data contribute to our knowledge of Canadian English at several levels of structure, including phonology, morpho-syntax, and lexicon. In this paper, the Montreal data are compared to those from the Toronto region and to earlier studies of Quebec English, in order to examine differences between the varieties of English spoken in Canada's two largest cities from a diachronic perspective. Contrary to the conclusion of an earlier study, variables involving a contrast between British and American forms show similar frequencies in both cities. The data on these variables also show the frequency of American forms in Montreal speech to be increasing over time. Another set of variables displays wide discrepancies between the two regions. Some of the differences are explained in terms of settlement history and language contact; others are not so easily explained and are presented as a challenge for future research.